WASHINGTON, D.C. -- The Department of Energy's National Nuclear Security Administration (NNSA) announced today that 63 kilograms (139 pounds) of highly enriched uranium (HEU) in spent nuclear fuel were safely and securely returned to Russia from Uzbekistan.

Four secret shipments under NNSA's Global Threat Reduction Initiative (GTRI) program have been conducted jointly by the United States, the Russian Federation, Uzbekistan, Kazakhstan, and the International Atomic Energy Agency (IAEA). The fourth and final shipment of the material, which could be used in a nuclear device or as part of a "dirty bomb," was completed yesterday. Most of the HEU spent fuel was enriched to 90 percent.

The shipments are part of a prioritized, accelerated schedule implementing a key element of a 2005 agreement between President George W. Bush and Russian President Vladimir Putin.

"These shipments of highly enriched uranium spent fuel are part of NNSA's efforts to make sure this type of material doesn't fall into the wrong hands. We will continue working hard with the international community to reduce stockpiles of high-risk, vulnerable material worldwide," NNSA Administrator Linton F. Brooks said. "It was only with the cooperation of Uzbekistan, Russia, Kazakhstan and the IAEA that we were able to successfully complete this important international nonproliferation mission."

Beginning in January, the shipments of HEU spent fuel from Uzbekistan have taken place under tight security. During each of the shipments, HEU spent fuel was packaged into Russian TK-19 spent fuel transportation casks and then trucked under guard from the Uzbekistan Institute of Nuclear Physics to a railroad station near the capital city Tashkent. At the railroad station, the secure casks were loaded into special railroad cars and shipped through Kazakhstan to a secure Russian facility near Chelyabinsk where the spent fuel will be reprocessed over the next several years.

Uzbekistan is the first country from which Russian-origin HEU spent fuel has been returned to Russia under the 2005 Presidential Joint Statement between Presidents Bush and Putin agreed to in Bratislava, Slovakia. The agreement helped enhance and accelerate nuclear site and material security work between the U.S. and Russia. A prioritized schedule was developed for the completion of all shipments of Russian-origin fresh and spent fuel currently stored outside of research reactor cores by 2006 and 2010 respectively.

The four shipments of HEU spent fuel from Uzbekistan have been conducted in the last four months as follows: 9.5 kilograms (64 assemblies) in January, 12.6 kilograms (64 assemblies) in February, 14.8 kilograms (64 assemblies) in March, and 25.6 kilograms (60 assemblies) in April.

The HEU, originally supplied to Uzbekistan by the Soviet Union, was used as fuel for the WWR-SM research reactor of the Institute of Nuclear Physics. Because the material was cooling for a long period of time it no longer emitted an immediate lethal dose of radiation as other spent fuel does, making it easier to handle and therefore vulnerable to theft or diversion.

The mission of GTRI is to identify, secure, recover and/or facilitate the final disposition of high-risk vulnerable nuclear and radiological materials around the world as quickly as possible.

Established by Congress in 2000, NNSA is a semi-autonomous agency within the U.S. Department of Energy responsible for enhancing national security through the military application of nuclear science. NNSA maintains and enhances the safety, security, reliability and performance of the U.S. nuclear weapons stockpile without nuclear testing; works to reduce global danger from weapons of mass destruction; provides the U.S. Navy with safe and effective nuclear propulsion; and responds to nuclear and radiological emergencies in the U.S. and abroad.